Which of the methods in the Task Bag interface could have been defined as a oneway operation? Give a general rule regarding the parameters and exceptions of oneway methods. In what way does the meaning of the oneway keyword differ from the remainder of IDL?

What will be an ideal response?

A oneway operation cannot have out or inout parameters, nor must it raise an exception because there is no reply message. No information can be sent back to the client. This rules out all of the Task Bag operations. The pairOut method might be made one way if its exception was not needed, for example if the server could guarantee to store every pair sent to it. However, oneway operations are generally implemented with maybe semantics, which is unacceptable in this case. Therefore the answer is none.
General rule. Return value void. No out or inout parameters, no user-defined exceptions.
The rest of IDL is for defining the interface of a remote object. But oneway is used to specify the required quality of delivery.